Longitudinally adjustable assembly for a bicycle seat

Abstract

A longitudinally adjustable assembly for a bicycle seat has a seat tube, a seat post and an auxiliary hoop device. The seat tube has an inner surface and multiple longitudinal grooves formed in the inner surface of the seat tube. The seat post is slidably inserted into the seat tube and has an outer surface and multiple protrusions. The protrusions are formed on and protrude out from the outer surface of the seat post. The protrusions are respectively slidably mounted in the longitudinal grooves to allow the seat post to longitudinally move along the seat tube. The auxiliary hoop device is mounted securely with the seat tube and around the seat post. Because the protrusions are slidably mounted in the longitudinal grooves and the auxiliary hoop device provides a pressing force for the seat post, a relative rotation between the seat post and the seat tube can be avoided.

1 . A longitudinally adjustable assembly for a bicycle seat comprising:
 a seat tube having
 a top end; 
 an inner surface; and 
 a tube connecting section formed on the inner surface of the seat tube; 
   a seat post slidably inserted into the seat tube and having
 an outer surface; and 
 a post connecting section formed on the outer surface of the seat post and connected with the tube connecting section to allow the seat post to longitudinally move along the seat tube; and 
   an auxiliary hoop device mounted securely in the top end of the seat tube, mounted securely around the seat post, being a unidirectional bearing and having
 a housing having
 an inner surface; and 
 multiple abutting surfaces formed at the inner surface of the housing and inclining in a same rotational direction, each abutting surface having a side and a convex section which is formed at the side; 
 
 a hoop having
 multiple hoop recesses respectively formed radially through the hoop at intervals, each hoop recess having an inner side surface; 
 
 multiple elastomers respectively formed at and protruding from the inner side surfaces of the hoop recesses; and 
 multiple abutting units respectively mounted in the hoop recesses and respectively pressed by the elastomers. 
   
     
     
         2 . The longitudinally adjustable assembly for a bicycle seat as claimed in  claim 1 , wherein
 the tube connecting section has multiple longitudinal grooves formed at intervals and in the inner surface of the seat tube;   the post connecting section has
 multiple protrusion recesses formed at intervals and in the outer surface of the seat post; and 
 multiple protrusions respectively mounted securely in and protruding out from the protrusion recesses and respectively slidably mounted in the longitudinal grooves.